Optimisation of protection in the medical exposure of recurrent adult patients due to computed tomography procedures: development of recurrent exposures reference levels.

OBJECTIVES: To assess the incidence (1 year) and the cumulative incidence (3 years) of the condition of patients accruing cumulative effective doses (CED) of ≥ 100 mSv and their variability among different hospitals. To establish and validate a reference level for the CED in patients with recurrent exposures (RERL) and provide a RERL value. METHODS: Data of CT exposure was collected in 9 similar hospitals. The database included 294,222 patient*years who underwent 442,278 CT exams in 3 years. The incidence proportion of patients with CED ≥ 100 mSv in a given year (I100;1) and the 3-year cumulative incidence of patients with CED ≥ 100 mSv over 3 consecutive years (I100;3) were calculated and compared among different institutions. RESULTS: I100;1 ranged from a minimum of 0.1% to a maximum of 5.1%. The percentage of recurrent patients was quite uniform among centres ranging from 23 to 38%. The I100;3 ranged from a minimum of 1.1 to 11.4%. There was a strong positive correlation between the third quartile values of yearly CED and yearly incidence (r = 0.90; R2 = 0.81; p < 0.0001). RERL value in our study was found at 34.0 mSv. CONCLUSION: The management of patients with recurrent exposures is highly variable among hospitals leading to a 50-fold variation in I100;1 and to a tenfold variation in I100;3. RERL could be established and used by taking as a RERL quantity the CED and as a RERL value the 75th percentile of the third quartiles of the distribution of the yearly CED obtained by surveying different hospitals. CLINICAL RELEVANCE STATEMENT: This is the first ever multicentre study that quantifies recurrent exposures in terms of incidence and cumulative incidence of patients with CED ≥ 100 mSv. RERL establishment and use could benefit the optimisation of radioprotection of patients with recurrent exposures. KEY POINTS: This is the first multicentre study estimating yearly incidence and 3-year cumulative incidence of patients with cumulative effective doses ≥ 100 mSv. In this study, a 50-fold inter centre variation between the maximum (5.1%) and the minimum value (0.1%) of yearly incidence of patients with cumulative effective doses ≥ 100 mSv was reported. The range of the 3-year cumulative incidence extended from 1.1 to 11.4% (a tenfold variation) The third quartile of the yearly cumulative effective doses in a centre showed a strong positive correlation with the yearly incidence of patients with cumulative effective doses ≥ 100 mSv, with a potential of being used to set reference levels for recurrent exposures.

Radiation protection in non-ionizing and ionizing body composition assessment procedures.

Body composition assessment (BCA) represents a valid instrument to evaluate nutritional status through the quantification of lean and fat tissue, in healthy subjects and sick patients. According to the clinical indication, body composition (BC) can be assessed by different modalities. To better analyze radiation risks for patients involved, BCA procedures can be divided into two main groups: the first based on the use of ionizing radiation (IR), involving dual energy X-ray absorptiometry (DXA) and computed tomography (CT), and others based on non-ionizing radiation (NIR) [magnetic resonance imaging (MRI)]. Ultrasound (US) techniques using mechanical waves represent a separate group. The purpose of our study was to analyze publications about IR and NIR effects in order to make physicians aware about the risks for patients undergoing medical procedures to assess BCA providing to guide them towards choosing the most suitable method. To this end we reported the biological effects of IR and NIR and their associated risks, with a special regard to the excess risk of death from radio-induced cancer. Furthermore, we reported and compared doses obtained from different IR techniques, giving practical indications on the optimization process. We also summarized current recommendations and limits for techniques employing NIR and US. The authors conclude that IR imaging procedures carry relatively small individual risks that are usually justified by the medical need of patients, especially when the optimization principle is applied. As regards NIR imaging procedures, a few studies have been conducted on interactions between electromagnetic fields involved in MR exam and biological tissue. To date, no clear link exists between MRI or associated magnetic and pulsed radio frequency (RF) fields and subsequent health risks, whereas acute effects such as tissue burns and phosphenes are well-known; as regards the DNA damage and the capability of NIR to break chemical bonds, they are not yet robustly demonstrated. MRI is thus considered to be very safe for BCA as well US procedures.

Medical radiological procedures: which information would be chosen for the report?

AIMS AND OBJECTIVES: The aim of this study was to properly define the information regarding patient exposure to Ionizing Radiations in the radiological report, according to the European Directive 2013/59/EURATOM (EU 2013/59 art.58(b)). For this purpose, we evaluated the results from other Member States EU 2013/59 transpositions and from Guidelines recommendation published by International Organizations involved in diagnostic radiology. A practical way for implementing art.58 is also traced. MATERIALS AND METHODS: Dosimetric quantities, such as exposure, absorbed dose and effective dose which may be included in radiological report, were first analyzed; then, in order to define international state of art of Member States EU 2013/59 transposition, a Web research using French, English, Spanish and German key words was performed. RESULTS: EU 2013/59 transposition for 5 Member States was reported. Especially regarding art.58, a European project reports that few European countries (11 of 28) have identified the dose metrics to be used in radiological report. Scientific organizations supporting clinical radiologists and medical physicists have published Guidelines reporting parameters useful to quantify the radiation output and to assess patient dose. CONCLUSIONS: Our research revealed that there is not a shared interpretation of patient exposure information to be included in radiological report. Nevertheless, according to scientific community, authors believe that the exposure is the most appropriate information that could be included in radiological report. Alternatively, but with more expensiveness, a risk index based on effective dose could be used. Moreover, the systematic exposure information recorded could be useful for dose estimates of population from medical exposure.

The new lens dose limit: implication for occupational radiation protection.

AIM AND OBJECTIVES: The aim of this article was to explore the implications of the new Euratom dose limit for occupational radiation protection in the context of medical occupational radiation exposures. The European Directive 2013/59/Euratom takes into account the new recommendations on reduction in the dose limit for the lens of the eye for planned occupational exposures released in 2012 by the International Commission on Radiological Protection (ICRP 118). MATERIALS AND METHODS: Different dose-monitoring procedures and devices were considered. Occupational eye lens doses reported by previous studies were analyzed, mainly considering workers involved in interventional procedures with X-rays. The current status of eye lens radiation protection and the main methods for dose reduction were investigated. RESULTS: The analysis showed that the workers, potentially exceeding the new limit, are clinical staff performing interventional procedures with a relatively high X-ray dose. Regarding radiological protection issues, the considered literature reports that the proper use of personal protective equipment may reduce the eye lens absorbed dose. CONCLUSION: The evaluation of the occupational eye lens dose is essential to establish which method of personal dose monitoring should be preferred. Furthermore, education and training about the right use of personal protective equipment are important for medical staff working with ionizing radiation.

Osteoporosis: what the clinician needs to know?

Osteoporosis is a common condition and an important cause of disability. For this reason, early detection of the disease and patients at higher risk of bone fractures is compulsory. In the recent years, conventional quantitative methods have been spreading for the diagnosis of osteoporosis; moreover, new improvements in computed tomography (CT) and magnetic resonance imaging (MRI) have been made in this field and imaging findings may correlate to the morphological and structural changes within the bone.

Magnetic Resonance Imaging in degenerative disease of the lumbar spine: Fat Saturation technique and contrast medium.

PURPOSE: To examine both anterior and posterior elements of the lumbar spine in patients with low back pain using MRI T2-weighted sequences with Fat Saturation (FS) and contrast enhanced T1-weighted sequences with FS. MATERIALS AND METHODS: Two thousand eight hundred and twenty (2820) patients (1628 male, 1192 female, mean age 54) presenting low back pain underwent MRI standard examination (Sagittal T1w TSE and T2w TSE, axial T1 SE) with the addition of sagittal and axial T2w Fat Sat (FS) sequences. Among all the patients, 987 (35%) have been studied adding Contrast Enhanced (CE) T1w FS sequences after administration of contrast medium. RESULTS: Among 987 patients studied with contrast medium, we found: active-inflammatory intervertebral osteochondrosis in 646 (65%) patients; degenerative-inflammatory changes in facet joints (facet joint effusion, synovitis, synovial cysts) in 462 (47%); spondylolysis in 69 (7%); degenerative-inflammatory changes of the flava, interspinous and supraspinous ligaments in 245 (25%); inflammatory changes of posterior perispinal muscles in 84 (8%) patients. CONCLUSIONS: In patients with suspected no-disc-related low back pain, the implementation of T2w FS and CE T1w FS sequences to the standard MR protocol could allow a better identification of degenerative-inflammatory changes more likely associated to the pain.

Diagnostic imaging of two related chronic diseases: Sarcopenia and Osteoporosis.

Sarcopenia and osteoporosis are two major health problems worldwide, responsible for a serious clinical and financial burden due to the increasing life expectancy. Both when presented as a single entity and, in particular, in the form of "osteosarcopenia", they lead to an important increased risk of falls, fractures, hospitalization and mortality. In dealing with these two pathological conditions, it is important to understand that between bone and muscle there is not only a functional correlation but also a close relationship in the development and in maintenance, which is well expressed by the concept of "bone-muscle unit". This close relationship agrees with the existence of a linear association between sarcopenia and osteoporosis, in particular in elderly population. It is mandatory, in the clinical assessment of both diseases, to do an early diagnosis or to delay as far as possible the appearance of an established form in order to prevent the onset of complications. The aim of this review is to present the different imaging modalities available for a non-invasive investigation of bone and muscle mass and quality in osteoporosis and sarcopenia, with their application and limitations.